This is a little risky task I want to try.
I have a 4 SATA III disks RAID10 array running on LSI (former 3ware) 9750-8i controller
with BBU (read and write cache enabled). In case of hardware failure ...

My datacenter says that each rack has primary and backup power on each rack. I assume this means there is a UPS for each server. Therefore, do I have any need of getting a BBU for the following setup?
...

I have a server with a UPS, life on battery is around 20-30mins, the server has a 2405/128MB without BBU, I am just confused as to do I really need a BBU card?
Surely if the UPS is working, during a ...

I am wondering what's the purpose of a BBU. My first understanding was, that it enables the cache to write the data to the disc during a power failure. But some specifications say that a BBU can hold ...